Celestia Forums

Hi,

is there a better texture for the sun, one which shows more sun's spots and spicules ?

Is it possible to have mass ejection from a star, in Celestia ? Maybe someone made a model of a star with apocalyptic hydrogen bridges and mass ejection ?

I've found two medium star textures in jpg format, but I'm unable to paste them on the Sun. I tried this .ssc code :

AltSurface "Soleil 1" "Sol"
{
Texture "suncyl1.jpg"
}

AltSurface "Soleil 2" "Sol"
{
Texture "gstarbig.jpg"
}

What is wrong with the sun ? I'm able to do a similar thing to any planet, but not the Sun. Why ? Can we use the altSurface option, from the pop-up menu, on a star ? Is this a bug ? Please help !

Hi Cham:

You can use the gstarbig texture or any other texture you like for the Sun, but you have to place it over the Sun as its own object, with a radius just slightly bigger than the Sun. It won't work as an alternate texture because the sun is a star in Celestia, and star textures do not accept alt textures, to the best of my knowledge.

Anyway, here is the ssc file that works great for gstarbig:

"Sun" "Sol"
{
Texture "gstarbig.jpg"
Emissive true
Radius 709000 #celestia Sol : 695705.371
Oblateness 0.009

EllipticalOrbit {
Period 1e10
SemiMajorAxis 1e-10
Eccentricity 0.00
Inclination 0.00
}

RotationPeriod 609.6
Obliquity 7.25
EquatorAscendingNode 75.62
}


Do not insert this in the main solarsys.ssc file for Celestia. Rather, create a new ssc file for it titled "Sun" and place the ssc file in your extras folder. Place the gstarbig texture in the medres folder in Celestia. To create a new ssc file, simply copy one that already exists in Celestia, rename it to "Sun", delete all of its contents, copy and paste the above entries into it, and save it once more. Its that simple.

By the way, there are two gstarbig textures circulating on the forum. One is more yellow than the other. I have the lighter yellow-white texture. You can get it at my website below.

Enjoy

Frank Gregorio

Thanks for your reply. I'll try the code.

And what is your web page URL ?

Also, do you have a texture of a proto-planet, a cracked one with lava ?

It works, but only with the gstarbig.jpg file. Why can't I use another texture, for example sun1.jpg ? I changed the file name in the code, and the sun1.jpg file is at the right place, in the medres folder near the gstarbig.jpg file. I don't understand.

Okay, I solved the problem. The sun1.jpg wasn't at the right format : 2000 by 1000 pixels. It's supposed to be 2048 by 1024.

But what is your web site ?

And a cracked planet in formation ?

Cham:
Click the "www" button at the foot of Frank's post - that'll take you to his website.

Grant

Cham:

If you go to my website (click the web link below) and download the file named Activity 7.2 Addons E.zip, you will find two separate planets in formation in the file. Unzip it directly to your Celestia main folder and it will install a "Protostar" add-on to your Extras folder. Inside the protostar is a solar system in formation with 2 planets. Both are cracked, new and volcanic with glowing lava, particularly on their night sides.

Examine the ssc file in the add-on and it will reveal that the protostar and its planets are placed in orbit around a star named HIP 500114. You may or may not have such a star in the Celestia data base. You can tell by launching Celestia after you have installed the protostar add-on, press [Enter], type HIP 500114, press [Enter] again and press the [G] key. If HIP 500114 is in your program database, you will go there and find a protostar nearby with the planets in it. If you go nowhere, then you do not have the star. Simply open the ssc file and change the star designation to any other one you wish. Pick one in the night sky and use its name. Save the ssc file and relaunch Celestia, go to that star and you will find your planet in formation. Alternatively, you can use the textures for your own purposes.

Enjoy

Frank G

The sun is yellow, but it has no texture...well...kind of. The atmosphere is yellow but the globe is white and beneath this white 'sheet' is where the texture lies, as I have flown beneath the white 'sheet' and can see the texture. Sol is the only star affected this way.
I have tried the advice given, by creating a ssc file for the sun and putting it in the extras folder and it worked...well...kind of. This time, as I approach the sun it flickers between white and texture.

To create a new ssc file, simply copy one that already exists in Celestia,

I'm using Celestia v1.3.1-1 OSX and checking the original download, I couldn't find a ssc file for the sun. There doesn't seem to be a ssc file for the sun, for this version...or more accurately, it's hiding elsewhere. I tried to find it in other files but no luck.

Help
Chris

Can I put an alternate texture over Betelguese in this way?
I've made this one


using information from this page (check out the movies! whew!)

http://www.aip.de/groups/sternphysik/stp/convect.html

If so, what would the ssc file for such an overlay look like?

eburacum45 wrote:Can I put an alternate texture over Betelguese in this way? ... If so, what would the ssc file for such an overlay look like?

Something like:


Grant

StarCrazy wrote:I'm using Celestia v1.3.1-1 OSX and checking the original download, I couldn't find a ssc file for the sun.

There is no ssc for the Sun - its appearance (like all the other stars) is generated automatically from the parameters in stars.dat.
The advice above is a way of building a huge fake "planet" surrounding the star itself, so that other textures can be used ... it's just a work-round because Celestia doesn't let us assign individual textures to stars.
What has happened when you've added an ssc for the Sun is that the fake planet has appeared, but Celestia can't find whatever texture you've specified, so it's colouring the surface white.

Grant

Thank you, Grant; that works fine.

granthutchison wrote:What has happened when you've added an ssc for the Sun is that the fake planet has appeared, but Celestia can't find whatever texture you've specified, so it's colouring the surface white.

Grant

Hi Grant, thanks for the reply.
The thing is, that the problem with the white surface exists without any ssc file created in the extra folders...I tried to use the above advice to overcome this...I'm now suspecting that something must be in the extras folder that's affecting sol, though, have tried to find it a couple of times with no luck...as well as replacing the star.dat.
I might as well just reinstall Celestia and sift through the add-ons later on tonight ...should do the trick

Thanks
Chris

StarCrazy wrote:The thing is, that the problem with the white surface exists without any ssc file created in the extra folders...I tried to use the above advice to overcome this...I'm now suspecting that something must be in the extras folder that's affecting sol ...

Yes, definitely. (Sorry I misunderstood you the first time.) You've got an add-on somewhere that's done half the job of changing the Sun's texture. Do you have any of Frank's educational activities installed? I know he changed the Sun texture at one time.

Grant

Do you have this Beteugelse alternative texture to download?I don?t find the link anywhere.

Star Crazy:

Before you reload Celestia, one of my activities does install and use "gstarbig.jpg" as a new solar texture overlaid on top of Sol. The add-on is in the Extras folder, inside a sub-folder called "Stars", and is titled "Sun". If Celestia is loading it, you should not see a big white ball, but a granular highly textured sun that is sized slightly larger than Sol. If the texture is not loading, then Celestia cannot find the jpg file that is supposed to accompany it, or there is some problem with file names to work out.

The easiest way to see if you have this add-on is to run Celestia, go to Sol and left-click on Sol in a variety of places. If the name changes from "Sol" to "Sun", then my add-on is running. To get rid of it, close Celestia, locate the Sun add-on in the extras folder and drag it out of the folder or delete it. If the name does not change when you click on the sun, then the problem is not my add-on, and more troubleshooting is in order.

Let me know how it goes.

Frank

I found a simple way to see 2 sun's textures.... I applied atmosphere to fsgregs' ssc:


"Sun" "Sol"
{
Texture "sol_soho.jpg"
Emissive true
Radius 709000 #celestia Sol : 695705.371
Oblateness 0.009


Atmosphere {
#Height 60
#Lower [ 0.43 0.52 0.65 ]
#Upper [ 0.26 0.47 0.84 ]
#Sky [ 0.40 0.6 1.0 ]

CloudHeight 7
CloudSpeed 5
CloudMap "gstar1k.jpg"
}


EllipticalOrbit {
Period 1e10
SemiMajorAxis 1e-10
Eccentricity 0.00
Inclination 0.00
}

RotationPeriod 609.6
Obliquity 7.25
EquatorAscendingNode 75.62
}


sol_soho.jpg is suncyl resized....

in this way u can change texture by pressing I on the keyboard